Just as there are 50 ways to leave your lover, there are 50 causes of rhabdomyolysis (16), including eight commonly reported categories of trauma, muscle hypoxia, genetic defects, infections, body temperature changes, metabolic or electrolyte disturbances, drugs or toxins, and exercise (2). When it comes to exertional rhabdomyolysis (ER), however, only one common cause exists: too much, too fast, too soon of an exercise too novel. We have known this for 50 yr, since the outbreaks of the "squat jump syndrome" in U.S. Marine platoons (7). The U.S. military experience also teaches how to prevent ER (3,11,12).
Yet, with each outbreak of ER in a team sport, as in high school football last year in Oregon (4) or in college football this year in Iowa - even after a detailed investigation - some coaches say they are baffled as to how or why this can happen (1). With 50 yr of history, Shakespeare should be right: what's past is prologue - to informed prevention. Instead, Faulkner was right: the past is not even past. The University of Iowa outbreak is an example.
Hawkeye Rhabdo: The Unlucky 13
The Hawkeye outbreak in January 2011 was widely covered, and the in-house investigative report is available online via media links (8). Two days after a 3-wk winter break, the football team was put through "the hardest one-day training regimen in the Iowa…playbook" (17). Some upper body work and sled pushing was done, but by far, the hardest task was 100 timed back squats at 50% top weight for one repetition. The strength coach told the team that losing close games during the prior season should concern everyone and that the workouts ahead would determine "who wants to be here" (17).
The report pinpoints the back-squat drill as the likely culprit, saying, "[We] are as certain as possible…that the strenuous squat lifting workout…caused rhabdo in the 13 who were hospitalized…." One player had dark urine the first night. The next day was upper body work; many players had severe leg pain, making it hard to don shoes or climb stairs; five more had dark urine. The next 2 d were the weekend; no workouts took place, but legs stayed sore, stiff, and weak, and four more players had dark urine. Monday brought speed workouts, but many players said their legs hurt so much they could not jump over the low hurdles; three more had dark urine. On Monday, one player saw an athletic trainer for hypertension; he was sent to a physician who diagnosed ER and then found it in four other players, all of whom he hospitalized. Word was spread, and by Tuesday, 13 football players were hospitalized with ER. None developed compartment syndrome or problematic renal failure; all were discharged as symptoms subsided during the next few days. All were cleared to return to play, but media reports 2 months later implied that not all 13 players were up to full speed and that 1 player was considering sitting out a year to regain his strength and weight (14).
The in-house investigative report, of course, found no wrongdoing and no evidence that the workout was for punishment, although the last time a similar workout had been done (December 2007) was 1 wk after another year that, like 2010, had disappointed coaches. That 2007 workout was recalled by players as very tough, making them very sore, making it hard to don shoes or climb stairs, but none recalled brown urine then. No such workout was done in 2008 or 2009, both strong winning years.
The report of the 2011 outbreak found that those with ER were more likely to have gone to muscle failure during the squats, to think they could not finish, and to do more squats because some were not counted as full squats. The risk of ER also increased with the number of sets and time needed to finish the 100 squats. In all but the linemen, the risk of ER increased with the amount of weight lifted as a percentage of body weight.
The report also says, "We learned that the strength and conditioning coaches were very aware of heat injury and dehydration but they did not know about ER until the cluster occurred…members of the football coaching staff and the strength coaches had not had prior experience with ER." On March 28, 2011, the National Strength and Conditioning Association spoke out on the Iowa outbreak, calling for strength coaches to get educated on ER and saying that "[ER] is not an expected or acceptable outcome of any training program…and is a sign that the training program was inappropriate for those athletes at that time of year."
Do Not Know Much About History?
No strength coach should be unaware of ER. This is like a scuba instructor being unaware of decompression sickness. Many articles on ER are in the medical and fitness literature. Even the CrossFit Journal publishes articles about it (6). In my column on the football ER outbreak in Oregon, I covered seven other cases or team clusters of upper extremity ER (4). Lower extremity ER as in Iowa has been reported in a college football kicker who did 300 squats (9) and in more than 50 prisoners who did up to 600 to 900 squats or squat thrusts (10,15). Besides the U.S. military experience with ER (3,7,11,12), major and fatal ER has been reported in police and firefighters in training (13). Three college wrestlers died of ER (with heat injury) in the fall of 1997. Fulminant ER tied to sickle cell trait is now the leading cause of death in Division 1 National Collegiate Athletic Association football conditioning (5).
How to Fix It?
Although the investigation of Iowa by Iowa found no wrongdoing, it presented some good ideas: 1) never again use the intense, high-volume squat workout; 2) educate everyone in the athletic department about ER and how to prevent it; 3) teach all athletes the warning signs of ER, and if a few develop it after a strenuous workout, test the entire team for it; 4) improve communication between strength coaches and health care staff, so that athletes are not cleared for inappropriate drills; and 5) disseminate this report, so others can learn from our experience.
The investigative committee speculated that the players had become deconditioned to some degree, especially fast-twitch fibers, during the 3-wk break. Some players agreed. The media too got the point, saying in effect that it was not smart to conduct their hardest workout right after a 3-wk holiday break (17). The head football coach? Not so much. He implied that no "smoking gun" was found. "To me, it would have been great [to find a cause]," he said, and although he promised to drop the workout in question, he also said, "I don't think we can [back off]" (1). Then he awarded the head strength coach the "Assistant Coach of the Year." This may speak to the limits of education.
Education could begin with what the Marines learned 50 yr ago. A seminal report of 60 cases of ER in recruits from "the squat jump syndrome" appeared in 1960 (7). Other reports followed, including an outbreak of ER that hospitalized 40 Marines in one platoon. Incidence and severity of ER varied within platoons and especially between platoons, according to fitness, prior physical conditioning, and type and intensity of exercise. Especially troubling was "high-intensity, repetitive exercise." Besides attention to hydration, diet, and rest, the first tip for prevention of ER in Marine recruits was emphasis on prolonged submaximal exercise, not repetitive exhaustive exercise (3,11,12).
In short, do not try to build Rome in a day. Even CrossFit has figured it out. They encountered major ER from brief sessions, where the athletes who came down with ER turned in marginal CrossFit performances but, during and right after the workouts, showed "no signs of discomfort that were out of the ordinary." CrossFit calls this "cold rhabdo" and says, "it seems abundantly clear [they] were exposed to too much work in too short a time...their previous training…proved woefully inadequate at preparing them for sustained power output" (6).
Maybe Iowa football can learn from the Marines and from CrossFit. As Eleanor Roosevelt said, "Learn from the mistakes of others. You can't live long enough to make them all yourself."
2. Bosch X, Poch E, Grau JM. Rhabdomyolysis and acute kidney injury. N. Engl. J. Med.
3. Demos MA, Gitin EL, Kagen LJ. Exercise myoglobinemia and acute exertional rhabdomyolysis. Arch. Intern. Med.
4. Eichner ER. An outbreak of muscle breakdown: a morality play in four acts. Curr. Sports Med. Rep.
5. Eichner ER. Sickle cell trait in sports. Curr. Sports Med. Rep.
6. Glassman G. CrossFit induced rhabdo. CrossFit J.
October 2005; 1-3.
7. Howenstine JA. Exertion-induced myoglobinuria and hemoglobinuria. Simulation of acute glomerulonephritis. JAMA.
9. Moeckel-Cole SA, Clarkson PM. Rhabdomyolysis in a collegiate football player. J. Strength Cond. Res.
10. Norquist C, LoVecchio F. The card game: outcomes after exercise-induced rhabdomyolysis in prisoners. Am. J. Emerg. Med.
11. Olerud JE, Homer LD, Carroll HW. Incidence of acute exertional rhabdomyolysis. Serum myoglobin and enzyme levels as indicators of muscle injury. Arch. Intern. Med.
12. Ritter WS, Stone MJ, Willerson JT. Reduction in exertional myoglobinemia after physical conditioning. Arch. Intern. Med.
13. Sandhu RS, Como JJ, Scalea TS. Renal failure and exercise-induced rhabdomyolysis in patients taking performance-enhancing compounds. J. Trauma.
15. Sinert R, Kohl L, Rainone T, Scalea T. Exercise-induced rhabdomyolysis. Ann. Emerg. Med.
16. Vanholder R, Sever MS, Erek E, Lameire N. Rhabdomyolysis. J. Am. Soc. Nephrol.